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b=WQw6WNVHoW/KS1hUY15Q0PkslgZvP+TZ1M0hUw53UBYSSKbljQ1nnM/X5n93S/I3A JvAJeGccjuWFWJQr+HI0/ttT5PXEv/1/S7MwOcIp1cgRts8JxIzc7+6q0y68E+vcdQ IjcY6aP5szF66JjI2H3eSBkmcmzqBQMtHtsN14UFsZzEf3F+HhgwA7AtEBxp1e3Cws 7c3brDrPJVm2LubAkN2f/JJIGRYImAvfavKx0reOTXi5MQcgHge5XvaLKQvErg5+ta MTTLlDMudFuMVZL8FuyIT24Gvg3/ysOSwrAHHM2x0aF/sDNfhmoJi+9R79XUVpo+Y5 LuvIG/EMIUghA== Date: Wed, 3 Sep 2025 20:39:18 -1000 From: Tejun Heo To: Roman Gushchin Cc: Alexei Starovoitov , Martin KaFai Lau , Kumar Kartikeya Dwivedi , linux-mm , bpf , Suren Baghdasaryan , Johannes Weiner , Michal Hocko , David Rientjes , Matt Bobrowski , Song Liu , Alexei Starovoitov , Andrew Morton , LKML Subject: Re: [PATCH v1 01/14] mm: introduce bpf struct ops for OOM handling Message-ID: References: <20250818170136.209169-2-roman.gushchin@linux.dev> <87ms7tldwo.fsf@linux.dev> <1f2711b1-d809-4063-804b-7b2a3c8d933e@linux.dev> <87wm6rwd4d.fsf@linux.dev> <87iki0n4lm.fsf@linux.dev> <87qzwnxgfr.fsf@linux.dev> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87qzwnxgfr.fsf@linux.dev> X-Rspamd-Server: rspam03 X-Rspam-User: X-Rspamd-Queue-Id: AB9A21C0009 X-Stat-Signature: 8y54u8hkwm1t3qbjdqtn7hch56z7adp7 X-HE-Tag: 1756967960-996710 X-HE-Meta: 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 suysWNU1 wiVTnCwhXCaSFWiYP4My9NCgnG9r+AFkZr3MF2FCDwGkoG+17i3aXRbtgprRzc2OrU5TK8cT+PrbCJlnisdJnmZGaDuIhBJOhbgOAS02jcfWONKkVSEtAeI9JqeqITs42hYtxnuCxirInGzBd/WxwTW3ci0yb5jf4x7AU9BRx+D11bII/C1HibCN9udZ0Hbj0azmyrU/RNfnXydXOkCPf1vD1d94mD0Fx9i3z8rKVMAm5x10kLlgpf23v1MclG5P4+QaT8J0AQRNNpqsYFnHgVTYkcNKZQ9heGhw5cKl4ZWtZ8pgpY5ZctuKQOA== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Hello, On Wed, Sep 03, 2025 at 04:30:16PM -0700, Roman Gushchin wrote: ... > > - I'm passing in cgroup_id as an optional field in struct_ops and then in > > enable path, look up the matching cgroup, verify it can attach there and > > insert and update data structures accordingly: > > > > https://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext.git/tree/kernel/sched/ext.c?h=scx-hier-prototype#n5280 > > Yeah, we discussed this option with Martin up in this thread. It doesn't > look as the best possible solution, but maybe the best we have at the moment. > > Ideally, I want something like this: > > void test_oom(void) > { > struct test_oom *skel; > int err, cgroup_fd; > > cgroup_fd = open(...); > if (cgroup_fd < 0) > goto cleanup; > > skel = test_oom__open_and_load(); > if (!skel) > goto cleanup; > > err = test_oom__attach_cgroup(skel, cgroup_fd); > if (CHECK_FAIL(err)) > goto cleanup; Yeah, that'd look better but are there practical differences? The only one I can think of is fs based permission check but that can be done separately too. Thanks. -- tejun